A147042 Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 0100-0100-1111-0100 pattern in any orientation.

1, 1, 1, 1, 1, 3, 13, 39, 151, 607, 2057, 13855, 94157, 812183, 7313331, 95388939, 1173110437

Offset

1,6

Links

Table of n, a(n) for n=1..17.

Example

Maximal 8 X 8 example
.0.1.0.0.0.1.0.0
.1.1.1.1.0.1.0.0
.0.1.0.0.1.1.1.1
.0.1.0.0.0.1.0.0
.0.0.1.0.0.0.1.0
.1.1.1.1.0.0.1.0
.0.0.1.0.1.1.1.1
.0.0.1.0.0.0.1.0

Crossrefs

Sequence in context: A103277 A166897 A167910 * A018492 A227446 A059020

Adjacent sequences: A147039 A147040 A147041 * A147043 A147044 A147045

Keyword

nonn

Author

R. H. Hardin, Nov 04 2008

Status

approved